SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a70d45f310b2efde1b2b7b072e0197ea454223bf82bdc9736960a3897fbfc56b' 
  AND token = 'HBBcMMR96qCA14xQfGnbT0GyJBknr/Djp/fK8lqPKvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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