SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9264e93635da7b96e4307402fd66c11eb65eaad45f1fa3a31fb3d41a76eccae1' 
  AND token = 'gBPT+eLJpIpkRUiewS5+Gw/6Hd2b/WuG54cjCLkJ/qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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