SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5c0bdf40af87f4a97b28ff968f7afb066827448804369ab666212bfae00bbc4' 
  AND token = 'FQBIlH8qCrc9YuwW2xv12CqwdxjcZ7UyYVo9g5KvBps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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