SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3a52ee9972fa02ce2392903f8d1f2adf9514e0133d29ee8ae480e21b4d727cbc' 
  AND token = 'xfUsF/dpje4iyiMPFVOeWWbVfTL1y0FUTbEF6hIrdTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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