SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da8f3a84849c04958119ddd66a502f062b59bee1b65d8931abc1232dd0272be5' 
  AND token = 'xn7bQkL/w2TV4Gt0mfFXY6Nfb/3t4PlAhdiIdaS1NxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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