SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f449662b8f665ae17ad83270f41f0c1c771e6419f8a79d2fdb049eb7f47fbaf' 
  AND token = 'zLHTcKEVri/idKn5VYl9+FITkFhKuzG9abisBYKfutI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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