SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5a068c3dfa0b48eb5f2b0587e14b77b727dcbed49272721395606813e1f178f' 
  AND token = 'b0hLCgplTvrUYfQN4owU+KcMGfzhNlzcLk8NRX3BheM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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