SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '495bf9ccf31c664f6d360418a735725786378ef15ac20142bfc0b2eadda7e8f6' 
  AND token = 'DOhQbwwSVuk+GYKgXo2uUlW4FQONbDPmVOSQtT58MqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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