SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '15b2b664675c90ef38b27e252929efc03f9f6c04323de0e50d2874278719995c' 
  AND token = 'YZ3gwgEGHf4U/SLP/PEohzCtKSVLtfyoTcP1ryjCcAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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