SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '753a776593726711e2ca87199a1a889751028192b292bf0b877bdadcd6ecc15e' 
  AND token = 'e5DV7wkM8SHziSnisncBtwhcf2tisHXdg/RiH6x6K00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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