SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5bb3aa81a87aa62cbd1d4f137a5ec46d2fe70e73c8422428aa08a153f89c587c' 
  AND token = '+krkjONQBbk2glALf0TqisusbB7zxEPUbVNBCy6kGCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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