SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73cfd447119f309010080a2a83bfd7f636b834eb2d65d4b2f05fdca86d4c7710' 
  AND token = '2YdPl+i1YknXmHKNHeQ1B6Q+5rTdSzxRr5tjHODdvDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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