SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3efb44ddd1fcfe1d0240004b5f64c286d3f72d669422315838ea23bef16518f' 
  AND token = 'HOVOl8fUUL1wNQaTqE+UL64wpIqhrpXrgSRfnkAo7QM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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