SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6cf337850f85c77fa98f0912dbe956f5e3a524ac3a79015f167494f907004b6' 
  AND token = 'BhquHBoaMUgzG5l4vdaM1fZ4gUYYq5ueGt89wNdPtNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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