SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4bdbf5e9e6f83a487c45b626a7e4d4266fd505651413b9650131983d17a37d7' 
  AND token = 'smGCUMFw0si4liNClzjxYQo/e0+l/r+kVWmy9CebAC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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