SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31cb5419ac0b8d00e1a80c6cec45b072f0c27f7590de57869b27fff971dfebab' 
  AND token = 'AmE8Ym8gxz0SRWHCfA2dsn8FCvfvoqLkHyy5YwhXNUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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