SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b99e33b412c5577ad368cb82cc77d701c2c4f402eecd57ee6d60f96065c6f095' 
  AND token = 'it9X01QwjsCi6nZ9nLBvytcrDZb7InIJidQUSfjWfX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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