SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ba0367191089c2e963221fe00585b546c80c12dc8b11ea69850c8232caed371' 
  AND token = 'U+u98aLptvOZUp5aUe0k+ad0u6T4Fdr5/KHiBLLQzTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}