SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '360bc3ed7f82bcad95022c3daae8fa47dc0aaef1cfc9d85c07860bfa9c1889b7' 
  AND token = 'nqyPVNTK8mTV8PhzNbJwsXmnj0oOq2/+2cewCj2UW4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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