SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42c541202e96d218fb41b8023a8b929183943788feb70a1011899deef6dcb9b2' 
  AND token = 'hpO8aSjNqus6H0eUeroiX9NcljbSGGO58JElA2Pq9Vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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