SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0545b32d8d0d16a4af0a7d15d3f31dba196bc72fd0a4e0bce34497bf742d1b85' 
  AND token = 'LCvmO4oRwUYFQhYb4fP3V+MUqyz1QNuxzOdEgI0YkxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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