SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'feaa2252c29fb08187980d28da1c83c27c6c03abf6542e2b53d1bfa77284a522' 
  AND token = '4iWnbZ6Ca8Vhuyrd4gmQn/D0v6b/uL1t/QHcdhO6MSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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