SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acd87e5ba4023638f051a4bf200bb73a7f7e2f11ebf0f5540af315279f000339' 
  AND token = '9TumSDsOQIfj/s2Y5GRk0T+F38OAXv/x14nehqP660w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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