SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '18db5be89676b3dc67e486b2764e5117f4f7e290d69b97caedbb7c0fd42aca40' 
  AND token = 'ZhXipBdDcRE3tTlCxiZB+qp3ALPO+HQrScYDyusE3/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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