SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5703f9567bc5fc8b0def3f12b19cba57d7f986722212ecf34fc2448d29620963' 
  AND token = 'ZOsK4sftX7ynwvEMxI0uOFjeCf5C+3gZ/+wDkV6QVFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00081

JSON explain

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