SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '418b5eb6625385027308bef6f9c1dbff0a3000e23eb0aa1038539ff259770953' 
  AND token = 'C/AdKJun7eVdksQqtdbWdWkoYq8Gl2trxEweg8GKiAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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