SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c7aada224cbc0c050d57702f3ef38bb31c9963a441de528d2dc29e5b023f62' 
  AND token = 'cYn3SkA8pzVNLaYQglpAuCgpnUER9DIUqY7cPQIGqR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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