SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eed62266cbf8df69519084114d65bdb1b9565711e0f0c87bf14cdde6ad0048c' 
  AND token = 'lwUBhgb7TYyVztINOX96bhv8OlL80lOOUFOlAs53KDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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