SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dc1f76e0dea24625e229046d47613cfd127a1309000abf78074b5f88ce2489fd' 
  AND token = 'GYdwsvH8jR06fsFcUwdfh9mKPR4MTiXDwckIFcMO7Xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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