SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3f5f6abf2a9e34b35dc54e21a8659cbed8ede51848e01a0b4a0baed053d8e01c' 
  AND token = 'tkqo8PCD6uSXNTDTfrGtPkeeBwuQ9SvTS7ZD/gtsNOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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