SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0a106672c52d7ae0bc60edd2e19c09d1fc0666df3a31cc4a6c0820f7e1762766' 
  AND token = '53ouIojGCoTxYHblVKVCUWwbJNPboOthp+MPETq2dWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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