SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a0379afad193c108014f74339f73257ae92bec3f4ec86a80b05bd2763024d93' 
  AND token = 'sjEZGVNeO2dr581ri+MBHEOeVr91OndMyhjlWZKt8tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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