SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce690cbaa534971c70b950fbce9930f598f7ea6819c6b43f1e3cdce1593a659c' 
  AND token = 'MOTFCdDmHFUrjQ9yxKKhdSjSq6StDsI30gmRZx/BCXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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