SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5d1af35875a965a66c692605e8b87a689eae64de1c969dd55cc18a9562e414c' 
  AND token = 'iQTd9CTwUbMnp3fAX4vJAdmFXbLw8Jy1p23fngxSrUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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