SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cde46c2b72c442b86ee3f39efa0b0ca4d04ded67e4fd8ee7666a78b7cc17da4' 
  AND token = 'lhGoxt8TJEfNwLy72Rjo4D36bsIbjY0mG7gWtcWT94Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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