SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbde437a1981ed20298694c5421bc1de78387b67bc86c1e62b9d23b57b6f5440' 
  AND token = 'kSMoMyYvr2RW6hV2pBgPrQGtgLBXl7WgzOQPjaGhru8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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