SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db1e5005b27d012803a6bca68b24c73a19cfbc4fc129be3817709393d6a4ec9f' 
  AND token = 'qgqRFClpZqSWMnuY4VfjsJQ/gwBm0JAA/mo4EOYptsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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