SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e32ce6c589147f1d493fedc56b07b49ac33673fe5a998418c93432b7f6383953' 
  AND token = 'SSSJIG/BZz8v7hrqui8WUJGwP4Wl37U1FQLSeyXMZJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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