SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1f792b706c2ac5d4e96a18328358d7c4263e8e66eafcbc899ebe140e3c7ebc5' 
  AND token = 'arInuIUTYQhdapBncCBj6EOMZyJ+8+/JGsEJaYhk/yI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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