SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee29d069af76d05b725c73113d235b6277218a3c94540ff8f8332004fe892bfd' 
  AND token = 'WRq2nhFZfcLmSDgZowlExXfuK/K2xwULgnlYRBBe/7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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