SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e7c7439d5298a500f2078f5104db69eaf5fc4f1563d60cf12f43c1d6e2ef4b7' 
  AND token = 'fDnP7mzH3Vc2RCSTLw+jO5XdLfEmM72TPNLBSpHA608=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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