SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '629c5a680aac84320442da7933936a715b4ce9f5c85537eb16d6b1f33e2f0148' 
  AND token = 'R1LvzTk4m52bkj3QPl/suXVGMXALwMaOJ+IAmEnnIjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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