SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7f000c39401cc9640ca91ddd7ad676ee88c0827de4bf81a70f2b4ad548606a9' 
  AND token = 'DK1UvZTv0JVBNn/Ah9LNgzksw8y/0wFN5RPq/tEuiXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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