SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45e476c4e38010196657b7c0c9384b1a9d3ac5a319df01c6959c21439f2e3248' 
  AND token = 'UGsB6QGub4KS2/IAUk7x+Jh3MAozZJShkpBgTU7Uf1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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