SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96be7a990950275210d67efbe8d1f388efef60f2a1649e4bdd11e40812b71a7b' 
  AND token = 'UiXjTeEtiSUgbiOzrUj97a6/vizJOucX80ge/2M3hzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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