SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dcdaa434fc7347710c39b884eceec6ba905f32383d5e307cc3f630bd8cd4cc5' 
  AND token = 'yjH+8TNm+MWWO3W9FyXrIrlAprRa7Pt8hOuWIdDqh7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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