SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc0ea57242fac2c9a2032cac3f57815483f8192fa6af2e106afbed703f3abd2c' 
  AND token = 'Q27AIHcGBP1xPIr8syfP3YufvvYRc56bQl5wC7yk8xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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