SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc87439409bb332f1f35f01f65b62d3a9df9f3a24b8299057732ceb6d40763d4' 
  AND token = 'q08AL7J77wOOQgkfdVqSQFzVFaJpR1hZu8t0oj1lrnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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