SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b8534989587f0ca81251fcdc434949070b925021a5103e1133329d23ba1a2e' 
  AND token = 'slAlvZiZ+eJnKFyrrKhERJZfxCFOkCH9P/LltNSu1jU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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