SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c9d1343ab532bc330223dfc7d035e3da640202357ea6abdd05abc4da0a79e67' 
  AND token = 'jHwg1Y9MdYatOSF/Bt6R2eid3h24oC6nuqGc8kX5U28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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