SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf50954e0b72435d5cb04395844a6ab01ecec4fe47dbcffea9fd11e4a81055a4' 
  AND token = 'n/G6bIcomw7kogpUsDiK8CgpnFUfG8/wZFXbqVp6q8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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