SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '339e9844c6f0f5063888d39d7db91544e720745e5fa41339ecbf61e3a2892c48' 
  AND token = '+Xdn0q4kIyzWDQWFM7XTa6XVxwKjmOSN1d5GrXHWq1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}