SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48fefc0db665553743ddb3e72ff0fbb43bea3bd22a4b2664c1bfe35e07741227' 
  AND token = 'HbZyVbjwCBe+yy5uzmFXWpW5oyeOrfLygJkEo5vCATE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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