SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20e52dadb275660fafc584f9b1f583536740b6fc521d43f055b7104b80d46a77' 
  AND token = 'zhxcZEDhZ+RHANEmJIMI1MDLQ0ytzsd6+ErqIUwOzJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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