SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b25e5899f17bfde42847186ac30d74ae9d740d2e635ff2c265ceaba7a72179dd' 
  AND token = 'vaN8geAYgCF8s2P/kscqKRAJOivHYHYPyzEez+noUmc=' 
  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"
    }
  }
}