SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '591125dff9f3cbfc2c51aaa1e32cf1173a16ecb4accafcf3d6e64bfa328a0754' 
  AND token = 'FVYCslk6uPJ3mmlWkkTkKm6Ux9eTFbimK+0awLQ58nM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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