SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea8de9a146841e46aae99ce4372c16c8512a4211d7079531e948240b056c9156' 
  AND token = '+UYDePgOMYqexAQAcyNToUBcZzwBFdqkQmwTTZnzquo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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