SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a17df7bbb8e3660e42dcf3b2e59f4ead2aade6f74b26f24fb0968a4d83116d9' 
  AND token = 'cvmO8iv4pJcs9HZy4NEgtlSjKC+vKrB8VzWgQEvn9PU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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