SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82dda93d0e008decc605f8ec7f748d4acd42e0cb25dd0794f962c748a264e700' 
  AND token = 'g4CiOXlsYXuQ554+QlIYEEAo53SMrjSh1VDNleWuh30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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