SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56aaf82997a312635fa2649c6a17373385ce097d12170385d6c37b7ba84b22f8' 
  AND token = '+69Fr/CkeSvFdp2g8QE/ixzPGcYYwm1rybxAgcTVJZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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