SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc45f3c8799b78e52611b206aba74566a883f43c84da149219d8dd33dc1ce6d4' 
  AND token = 'g0h/9no0N9FXpLYTQNC4DCG8DblhaWERq7kdZD+roHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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