SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '297d5383f4a5c1310b802163e419174d826d27d4252f7592a4939b478068e006' 
  AND token = 'BlMhsMZxew9wpjGG155VI7IIcwrFddqs+bq2z0rSbVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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