SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a869cbed7d52d8bb99e91db918556a1904075af63280f2dfe69db83149e6802' 
  AND token = 'mjTB0PjYAqbSgH/QHjgt+6xBPW9w1EqZFZI7VDCiSL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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