SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'decca7065292147519f68aca07f3d52bfa3b4e3844724ce50e0067601c8213cd' 
  AND token = 'LjRvwilIm1REpZLh2djb9oujCBcsxCixXf2pKCsh6gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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