SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e24f30988d2c62483722b916f68dc05642df9519684df413a62c6373dccd2bfc' 
  AND token = 'qR9w/mP5bugNJLKOmojOKQ4tHXAqwu9FHDuQyzbN5CA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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