SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bb2ed64e506c086be5aa6f0d822a24e241d2ee5ec1bb38f5e680009ba42115b' 
  AND token = 'qb770H6efL8cyZWmfsDw+FsC+jT3noPmaHSwp7SzW2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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