SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fcd1da7115b3520ec2fb57b4e03ef66109bdffe020debc09c126ef3aae06e86' 
  AND token = 'YlLxQ1waxPtF5zvyEYnCNotUTsE5Bghx2yxace6fvMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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