SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbad7896486526483284451218c427b487693c2bbecc5b80f461721cae096fb7' 
  AND token = 'lpEWX75qL6wqApLu3VuJUVut+IRyRSIbSOBMae582CM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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