SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67975aa45c67c4f3248a530a5f3815557b176c419870daedf4fd6e2bd1181c7d' 
  AND token = 'C66ltNUoXTtUkobdrYs79HtxVyiz+PUTM7F3DL1gGRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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