SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5585cd0474c9a59317cc8ad6695f960953fa3ee7226151f9a91769ed6d726e63' 
  AND token = 'HnzAguWtf4ohTu1qUsHwAG9CWHIZOXsFVnVhUDXgzN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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