SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b82dd6d2853f1298b12f92873f8fadd40fcd17d3af3ebc213dd216f03b7f6b3' 
  AND token = 'MPuIbOHupH0MhjKVOpQ4g0TQR2YblKMnvq2dOZdeDyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}