SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b703768fe76927431a72540805acfed77d0a543d735704d44570c30366b5de7' 
  AND token = 'tb22celE1zofPVvANvLIUTavEFMO0YNoqI2oCjhQWz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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