SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70b0f38e06b7d37ec6501c234f80c4e1e831cce9d870c5020464df9751c2ca56' 
  AND token = 'UyI7GIMeSzstYi0duDcupGOMpZ5ZEyPcHS5MPfK5tI8=' 
  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"
    }
  }
}