SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ded70a92b3bfa94ef8c6e02a8f50607573e4fdb8ef1c77a98655af47ead1619' 
  AND token = 'UIzcvyz0/fBQRmwCO45qTKfgtFi0588ThgR/QIjHjNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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